In electrical equipment which emits laser light signals to a connected optical fiber, precautions need to be taken to prevent high energy laser light from escaping from the equipment when the optical fiber is not connected, thus endangering the eyesight of an operator.
In the prior art, a safety device comprising a mechanial shutter which only opens when a optical fiber is connected could serve to prevent the escape of laser light. However, such use of a mechanical device could damage the optical fiber, as optical fibers are extremely delicate mechanically, and are frequently manufactured with tolerances in the micrometer range.